Allow mbrtowc() and wcrtomb() to be implemented directly, instead of

as wrappers around the deprecated 4.4BSD rune functions. This paves the
way for state-dependent encodings, which the rune API does not support.
- Add __emulated_sgetrune() and __emulated_sputrune(), which are
  implementations of sgetrune() and sputrune() in terms of
  mbrtowc() and wcrtomb().
- Rename the old rune-wrapper mbrtowc() and wcrtomb() functions to
  __emulated_mbrtowc() and __emulated_wcrtomb().
- Add __mbrtowc and __wcrtomb function pointers, which point to the
  current locale's conversion functions, or the __emulated versions.
- Implement mbrtowc() and wcrtomb() as calls to these function pointers.
- Make the "NONE" encoding implement mbrtowc() and wcrtomb() directly.

All of this emulation mess will be removed, together with rune support,
in FreeBSD 6.

7 files changed, 204 insertions, 50 deletions

diff --git a/lib/libc/locale/Makefile.inc b/lib/libc/locale/Makefile.inc
index 23ea555..9003321 100644
--- a/lib/libc/locale/Makefile.inc
+++ b/lib/libc/locale/Makefile.inc
@@ -10,7 +10,8 @@ SRCS+=	big5.c btowc.c collate.c collcmp.c euc.c fix_grouping.c frune.c \
 	mbrlen.c \
 	mbrtowc.c mbrune.c mbsinit.c mbsrtowcs.c mbtowc.c mbstowcs.c \
 	mskanji.c nl_langinfo.c nomacros.c none.c rune.c \
-	runetype.c setinvalidrune.c setlocale.c setrunelocale.c table.c \
+	runetype.c setinvalidrune.c setlocale.c setrunelocale.c srune.c \
+	table.c \
 	tolower.c toupper.c utf2.c utf8.c wcrtomb.c wcsrtombs.c wcsftime.c \
 	wcstof.c wcstod.c \
 	wcstoimax.c wcstol.c wcstold.c wcstoll.c \
diff --git a/lib/libc/locale/mbrtowc.c b/lib/libc/locale/mbrtowc.c
index 7e4d90e..e993082 100644
--- a/lib/libc/locale/mbrtowc.c
+++ b/lib/libc/locale/mbrtowc.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2002 Tim J. Robbins.
+ * Copyright (c) 2002, 2003 Tim J. Robbins.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,9 +32,24 @@ __FBSDID("$FreeBSD$");
 #include <stdlib.h>
 #include <wchar.h>
 
+extern size_t (*__mbrtowc)(wchar_t * __restrict, const char * __restrict,
+    size_t, mbstate_t * __restrict);
+
+size_t
+mbrtowc(wchar_t * __restrict pwc, const char * __restrict s,
+    size_t n, mbstate_t * __restrict ps)
+{
+
+	return (__mbrtowc(pwc, s, n, ps));
+}
+
+/*
+ * Emulate the ISO C mbrtowc() function in terms of the deprecated
+ * 4.4BSD sgetrune() function.
+ */
 size_t
-mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
-    mbstate_t * __restrict ps __unused)
+__emulated_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s,
+    size_t n, mbstate_t * __restrict ps __unused)
 {
         const char *e;
         rune_t r;
diff --git a/lib/libc/locale/none.c b/lib/libc/locale/none.c
index 1b1dc70..3c4d8c7 100644
--- a/lib/libc/locale/none.c
+++ b/lib/libc/locale/none.c
@@ -1,4 +1,5 @@
 /*-
+ * Copyright (c) 2002, 2003 Tim J. Robbins. All rights reserved.
  * Copyright (c) 1993
  *	The Regents of the University of California.  All rights reserved.
  *
@@ -40,60 +41,62 @@ static char sccsid[] = "@(#)none.c	8.1 (Berkeley) 6/4/93";
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <errno.h>
 #include <limits.h>
+#include <runetype.h>
 #include <stddef.h>
 #include <stdio.h>
-#include <rune.h>
 #include <stdlib.h>
+#include <wchar.h>
 
-rune_t	_none_sgetrune(const char *, size_t, char const **);
-int	_none_sputrune(rune_t, char *, size_t, char **);
+extern size_t (*__mbrtowc)(wchar_t * __restrict, const char * __restrict,
+    size_t, mbstate_t * __restrict);
+extern size_t (*__wcrtomb)(char * __restrict, wchar_t, mbstate_t * __restrict);
+
+int	_none_init(_RuneLocale *);
+size_t	_none_mbrtowc(wchar_t * __restrict, const char * __restrict, size_t,
+	    mbstate_t * __restrict);
+size_t	_none_wcrtomb(char * __restrict, wchar_t, mbstate_t * __restrict);
 
 int
-_none_init(rl)
-	_RuneLocale *rl;
+_none_init(_RuneLocale *rl)
 {
-	rl->sgetrune = _none_sgetrune;
-	rl->sputrune = _none_sputrune;
+
+	__mbrtowc = _none_mbrtowc;
+	__wcrtomb = _none_wcrtomb;
 	_CurrentRuneLocale = rl;
 	__mb_cur_max = 1;
 	return(0);
 }
 
-rune_t
-_none_sgetrune(string, n, result)
-	const char *string;
-	size_t n;
-	char const **result;
+size_t
+_none_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
+    mbstate_t * __restrict ps __unused)
 {
-	if (n < 1) {
-		if (result)
-			*result = string;
-		return(_INVALID_RUNE);
-	}
-	if (result)
-		*result = string + 1;
-	return(*string & 0xff);
+
+	if (s == NULL)
+		/* Reset to initial shift state (no-op) */
+		return (0);
+	if (n == 0)
+		/* Incomplete multibyte sequence */
+		return ((size_t)-2);
+	if (pwc != NULL)
+		*pwc = (unsigned char)*s;
+	return (*s == '\0' ? 0 : 1);
 }
 
-int
-_none_sputrune(c, string, n, result)
-	rune_t c;
-	char *string, **result;
-	size_t n;
+size_t
+_none_wcrtomb(char * __restrict s, wchar_t wc,
+    mbstate_t * __restrict ps __unused)
 {
-	if (n >= 1) {
-		if (string) {
-			if (c < 0 || c > UCHAR_MAX) {
-				if (result)
-					*result = NULL;
-				return (0);
-			}
-			*string = c;
-		}
-		if (result)
-			*result = string + 1;
-	} else if (result)
-		*result = (char *)0;
-	return(1);
+
+	if (s == NULL)
+		/* Reset to initial shift state (no-op) */
+		return (1);
+	if (wc < 0 || wc > UCHAR_MAX) {
+		errno = EILSEQ;
+		return ((size_t)-1);
+	}
+	*s = (unsigned char)wc;
+	return (1);
 }
diff --git a/lib/libc/locale/setrunelocale.c b/lib/libc/locale/setrunelocale.c
index 9cdd7e7..0037f9c 100644
--- a/lib/libc/locale/setrunelocale.c
+++ b/lib/libc/locale/setrunelocale.c
@@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$");
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <wchar.h>
 #include "ldpart.h"
 #include "setlocale.h"
 
@@ -60,6 +61,16 @@ extern int		_BIG5_init(_RuneLocale *);
 extern int		_MSKanji_init(_RuneLocale *);
 extern _RuneLocale	*_Read_RuneMagi(FILE *);
 
+extern size_t (*__mbrtowc)(wchar_t * __restrict, const char * __restrict,
+    size_t, mbstate_t * __restrict);
+extern size_t (*__wcrtomb)(char * __restrict, wchar_t, mbstate_t * __restrict);
+extern size_t __emulated_mbrtowc(wchar_t * __restrict, const char * __restrict,
+    size_t, mbstate_t * __restrict ps);
+extern size_t __emulated_wcrtomb(char * __restrict, wchar_t,
+    mbstate_t * __restrict ps);
+extern rune_t __emulated_sgetrune(const char *, size_t, const char **);
+extern int __emulated_sputrune(rune_t, char *, size_t, char **);
+
 static int		__setrunelocale(const char *);
 
 __warn_references(setrunelocale, "warning: setrunelocale() is deprecated. See setrunelocale(3).");
@@ -132,6 +143,10 @@ __setrunelocale(const char *encoding)
 	}
 	(void)fclose(fp);
 
+	__mbrtowc = __emulated_mbrtowc;
+	__wcrtomb = __emulated_wcrtomb;
+	rl->sputrune = __emulated_sputrune;
+	rl->sgetrune = __emulated_sgetrune;
 	if (strcmp(rl->encoding, "NONE") == 0)
 		ret = _none_init(rl);
 	else if (strcmp(rl->encoding, "UTF2") == 0)
diff --git a/lib/libc/locale/srune.c b/lib/libc/locale/srune.c
new file mode 100644
index 0000000..86d40a7
--- /dev/null
+++ b/lib/libc/locale/srune.c
@@ -0,0 +1,94 @@
+/*-
+ * Copyright (c) 2003 Tim J. Robbins
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <limits.h>
+#include <rune.h>
+#include <wchar.h>
+
+/*
+ * Emulate the deprecated 4.4BSD sgetrune() function in terms of
+ * the ISO C mbrtowc() function.
+ */
+rune_t
+__emulated_sgetrune(const char *string, size_t n, const char **result)
+{
+	wchar_t wc;
+	size_t nconv;
+
+	/*
+	 * Pass a NULL conversion state to mbrtowc() since multibyte
+	 * conversion states are not supported.
+	 */
+	nconv = mbrtowc(&wc, string, n, NULL);
+	if (nconv == (size_t)-2) {
+		if (result != NULL)
+			*result = string;
+		return (_INVALID_RUNE);
+	}
+	if (nconv == (size_t)-1) {
+		if (result != NULL)
+			*result = string + 1;
+		return (_INVALID_RUNE);
+	}
+	if (nconv == 0)
+		nconv = 1;
+	if (result != NULL)
+		*result = string + nconv;
+	return ((rune_t)wc);
+}
+
+/*
+ * Emulate the deprecated 4.4BSD sputrune() function in terms of
+ * the ISO C wcrtomb() function.
+ */
+int
+__emulated_sputrune(rune_t rune, char *string, size_t n, char **result)
+{
+	char buf[MB_LEN_MAX];
+	size_t nconv;
+
+	nconv = wcrtomb(buf, (wchar_t)rune, NULL);
+	if (nconv == (size_t)-1) {
+		if (result != NULL)
+			*result = NULL;
+		return (0);
+	}
+	if (string == NULL) {
+		if (result != NULL)
+			*result = (char *)0 + nconv;
+	} else if (n >= nconv) {
+		memcpy(string, buf, nconv);
+		if (result != NULL)
+			*result = string + nconv;
+	} else {
+		if (result != NULL)
+			*result = NULL;
+	}
+	return (nconv);
+}
diff --git a/lib/libc/locale/table.c b/lib/libc/locale/table.c
index b21ba0c..6497a24 100644
--- a/lib/libc/locale/table.c
+++ b/lib/libc/locale/table.c
@@ -42,15 +42,24 @@ __FBSDID("$FreeBSD$");
 
 #include <ctype.h>
 #include <rune.h>
+#include <wchar.h>
 
-extern rune_t	_none_sgetrune(const char *, size_t, char const **);
-extern int	_none_sputrune(rune_t, char *, size_t, char **);
+extern size_t	_none_mbrtowc(wchar_t * __restrict, const char * __restrict, size_t,
+		    mbstate_t * __restrict);
+extern size_t	_none_wcrtomb(char * __restrict, wchar_t, mbstate_t * __restrict);
+extern size_t	__emulated_mbrtowc(wchar_t * __restrict,
+		    const char * __restrict, size_t,
+		    mbstate_t * __restrict ps);
+extern size_t	__emulated_wcrtomb(char * __restrict, wchar_t,
+		    mbstate_t * __restrict ps);
+extern rune_t	__emulated_sgetrune(const char *, size_t, const char **);
+extern int	__emulated_sputrune(rune_t, char *, size_t, char **);
 
 _RuneLocale _DefaultRuneLocale = {
     _RUNE_MAGIC_1,
     "NONE",
-    _none_sgetrune,
-    _none_sputrune,
+    __emulated_sgetrune,
+    __emulated_sputrune,
     0xFFFD,
 
     {	/*00*/	_CTYPE_C,
@@ -253,4 +262,7 @@ _RuneLocale _DefaultRuneLocale = {
 _RuneLocale *_CurrentRuneLocale = &_DefaultRuneLocale;
 
 int __mb_cur_max = 1;
-
+size_t (*__mbrtowc)(wchar_t * __restrict, const char * __restrict, size_t,
+    mbstate_t * __restrict) = _none_mbrtowc;
+size_t (*__wcrtomb)(char * __restrict, wchar_t, mbstate_t * __restrict) =
+    _none_wcrtomb;
diff --git a/lib/libc/locale/wcrtomb.c b/lib/libc/locale/wcrtomb.c
index 7bebd1a..cd1c45b 100644
--- a/lib/libc/locale/wcrtomb.c
+++ b/lib/libc/locale/wcrtomb.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2002 Tim J. Robbins.
+ * Copyright (c) 2002, 2003 Tim J. Robbins.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,8 +33,22 @@ __FBSDID("$FreeBSD$");
 #include <stdlib.h>
 #include <wchar.h>
 
+extern size_t (*__wcrtomb)(char * __restrict, wchar_t, mbstate_t * __restrict);
+
+size_t
+wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
+{
+
+	return (__wcrtomb(s, wc, ps));
+}
+
+/*
+ * Emulate the ISO C wcrtomb() function in terms of the deprecated
+ * 4.4BSD sputrune() function.
+ */
 size_t
-wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps __unused)
+__emulated_wcrtomb(char * __restrict s, wchar_t wc,
+    mbstate_t * __restrict ps __unused)
 {
 	char *e;
 	char buf[MB_LEN_MAX];